The present invention is directed to an endless belt and method of making it for use in digital imaging systems, and more particularly, to such a seamless, reinforced belt which may be used in intermediate image transfer, toner fusing or transfusing, and/or sheet transport operations.
Digital imaging systems are widely used in the fields of xerography and electrography where dry or liquid toner is used to print text and graphic images. For example, systems which use digitally addressable writing heads to form latent images include laser, light-emitting diode, and electron beam printers. Copiers use optical means to form latent images. Regardless of how they are formed, the latent images are inked (or toned), transferred and fixed to a paper or polymer substrate. Such systems typically include a component such as an endless belt, roll or drum which is utilized for latent image recording, intermediate image transfer (transfer of a toner image to the belt followed by transfer to a substrate), transfusing of toner (transport of the unfused image onto the belt with subsequent fusing), contact fusing, or electrostatic and/or frictional transport of imaging substrates such as paper, transparencies, etc.
In the case of endless belts, such belts are typically moved or driven under appropriate traction and tension by rotating cylindrical rollers. As such belts play a critical role in the imaging or substrate transport process, they must be engineered to meet exacting standards. For example, image transfer belts must be seamless, flexible, and must exhibit uniform flatness. Further, the belts should provide certain electrical properties (dielectric constant, volume and surface resistivity, etc.) chemical properties (resistance to humidity, UV light, etc.) and dimensional specifications (circumference, thickness, width, etc.) which may vary depending on the desired application.
If the belts include nonuniformities as manufactured or in operation, various problems arise. For example, where the belts are used for latent image recording, surface flatness is of critical importance as the surface of the belt may be electrostatically charged using high resolution laser beams positioned over the belt. If the belt is not uniformly flat, image quality may suffer due to randomly localized deformation.
Accordingly, there is still a need in the art for an endless belt for use in digital imaging systems which can be manufactured and operated to be within exacting tolerances, including surface flatness, and which may be used for a wide variety of imaging, image transfer or sheet transport operations.